In November 2023 Merck, which is known as MSD outside the US and Canada, announced results from a Phase III trial evaluating the company’s investigational 21-valent pneumococcal conjugate vaccine for protection of adults. The release was followed up by details shared at the World Vaccine Congress West Coast on the same day. The trial, STRIDE-3, evaluated the immunogenicity, tolerability, and safety of V116 in comparison with PCV20 in adults who had not previously received a pneumococcal vaccine.
V116
V116 is an investigational, 21-valent pneumococcal conjugate vaccine for the prevention of invasive pneumococcal disease and pneumococcal pneumonia in the adult population. It is “specifically designed” to address Streptococcus pneumoniae serotypes that are predominantly responsible for adult pneumococcal disease, included eight that account for approximately 30% of adult disease. CDC data from 2018-2021 indicate that the serotypes covered by V116 are responsible for around 83% of invasive pneumococcal disease in adults aged 65 and older.
What does the study find?
Results from STRIDE-3 primary objectives include:
In adults aged 50 and above (Cohort 1), V116 elicited non-inferior immune responses compared to PCV20 for all 10 serotypes common to both vaccines as measured by serotype-specific opsonophagocytic activity (OPA) geometric mean titers (GMT) at Day 30.
Immune responses elicited by V116 were superior for 10 of 11 serotypes included in V116 but not in PCV20 as measured by OPA GMT at Day 30 and the proportions of patients with a greater than or equal to four-fold increase in OPA from Day 1 to Day 30.
In adults between the ages of 18 and 49 (Cohort 2), V116 elicited non-inferior immune responses (immunobridged) compared to adults between the ages of 50 and 64, as assessed by serotype specific OPA GMTs 30 days after vaccination.
Across both cohorts, V116 had a safety profile comparable to PCV20.
The Phase III clinical development programme comprises eight trials in various adult populations, including adults with and without chronic medical conditions associated with increased risk of pneumococcal disease.
Exciting potential
Dr Eliav Barr, senior vice president, head of global clinical development, and chief medical officer at Merck Research Laboratories, is “excited by the potential” the vaccine has, to shape public health.
“These results provide strong evidence to support the immunogenicity of V116 compared to the standard of care in the prevention of invasive pneumococcal disease and pneumococcal pneumonia in adults.”
Principal Investigator of the study, Dr Sady Alpizar of Clinical Research Trials of Florida, Inc., commented that “invasive forms” of the disease can cause “serious and sometimes life-threatening complications”.
“These encouraging results demonstrate the V116 has the potential to help prevent invasive pneumococcal disease among vulnerable populations.”
We were glad to hear more from Dr Heather Platt and Dr Morgan Monslow yesterday in their sessions at the Congress in Santa Clara. If you weren’t able to join us do make sure you subscribe for more insights here.
